Uterus Sampling Devices
Devices that can be inserted into the uterus have been developed for endometrial sampling, pregnancy prevention, and other gynecological procedures. Examples include the select cell, transcervical devices, intrauterine devices (IUDs), and curettes. IUDs are small devices implanted into the uterus for a certain period of time to prevent pregnancy by disrupting the uterine wall or slowly releasing hormones. (Stubbs E, Schamp A. The evidence is in. Why are IUDs still out? Family physicians' perceptions of risk and indications. Can Fam Physician. 2008; 54(4):560-566; Heinberg E M, McCoy T W, Pasic R. The Perforated Intrauterine Device: Endoscopic Retrieval. JSLS. 2008; 12(1):97-100; The ESHRE Capri Workshop Group. Intrauterine devices and intrauterine systems. Human Reproduction Update. 2008; 14(3):197-200). The curette is a metal rod with a handle at one end and a loop on the other end that is used to scrape the lining of the uterus during a gynecological procedure called “dilation and curettage”. (Humber N. The occasional D & C. Can J Rural Med. 2009; 14(3):115-118). This procedure was considered the gold standard for sampling the endometrium for more than a century. (Chambers J T, Chambers S K. Endometrial Sampling: When? Where? Why? With What? Clinical Obstetrics and Gynecology. 1992; 35(1):28-39; Cooper J M, Erickson M L. Endmetrial Sampling Techniques in the Diagnosis of Abnormal Uterine Bleeding. Obstetrics and Gynecology Clinics of North America. 2000; 27(2):235-244)
In 1949, Guilbeau et al. proposed a uterine culture technique for sampling the endometrium of postpartum women while avoiding the contaminated cervical and vaginal areas. (Guilbeau J A, Schaub I G. Uterine Culture Technique: A simple Method for Avoiding Contamination by the Cervical and Vaginal Flora. American Journal of Obstetrics & Gynecology. 1949:407-410; Knuppel R, Scerbo J, Dzink J, Mitchell G, Cetrulo C, Barlett J. Quantitive Transcervical Uterine Cultures With a New Device. Obstetrics and Gynecology. 1981; 57:243-247; Duff P, Gibbs R, Blanco J, St. Clair P. Endometrial Culture Techniques in Puerperal Patients. Obstetrics and Gynecology. 1983; 61(2):217-222). They suggested using a metal tube with a tightly drawn finger cot (which required chemical sterilization for 48 hours) to occlude the distal end of the cervix and prevent contamination during insertion. Once inserted with a stylet beyond the internal os of the cervix, the finger cot was pierced, thus allowing the inner wire loop to collect the sample. However, this technique was merely described; no data were presented to document its efficacy.
In 1981, Knuppel et al. presented a transcervical device for sampling the uterus. (Knuppel R, Scerbo J, Dzink J, Mitchell G, Cetrulo C, Barlett J. Quantitive Transcervical Uterine Cultures With a New Device. Obstetrics and Gynecology. 1981; 57:243-247). This specimen collection device consisted of a telescoping Teflon catheter that housed a nylon bristle brush attached to a retractable wire in the inner cannula. At the tip of the outer catheter was a plug made of either gelfoam or polyethylene glycol. Upon insertion of the device, the brush was used to push the plug into the uterus to allow the brush to collect the specimen. Leaving the plug in the uterus was a major drawback. A plug made of polyethylene glycol would take a couple of days to dissolve; a plug made of gelfoam could cause a nidus of infection. This device was designed to pass through the contaminated vaginal and cervical area to the uterus for specimen collection. This device does not protect the uterine sample from the contaminated vagina and cervix, and it leaves the plug portion of the device inside the uterus.
Another technique for culturing the uterus was described by Bollinger. (Duff P, Gibbs R, Blanco J, St. Clair P. Endometrial Culture Techniques in Puerperal Patients. Obstetrics and Gynecology. 1983; 61(2):217-222; Bollinger C C. Bacterial Flora of the Nonpregnant Uterus: A New Culture Technic. Obstetrics and Gynecology. 1964; 23(2):251-255). In this technique, a Teflon sheath with a Teflon plug was used to reach the uterus. Once inside the uterus, the plug was dislodged by an inner cannula to which a syringe was attached for suction of the specimen sample. The accuracy of this approach was not clearly defined due to the fact that the device used for sampling passes through the contaminated areas of the cervix and vagina.
Between 1981 and 1982, Patrick Duff and his team investigated four different endometrial specimen techniques: (1) transfundal aspiration, (2) transcervical brush biopsy through a double-lumen catheter, (3) transcervical lavage through a double-lumen catheter, and (4) aspiration of secretions from the lower uterine segment through a single-lumen catheter. (Duff P, Gibbs R, Blanco J, St. Clair P. Endometrial Culture Techniques in Puerperal Patients. Obstetrics and Gynecology. 1983; 61(2):217-222). For the transfundal aspiration, an 18-gauge spinal needle preloaded with sterile polyionic solution is used. Once in the endometrium cavity, the solution was injected through the needle and then immediately aspirated back into the needle. Knuppel et al described the transcervical double-lumen catheter technique. (Knuppel R, Scerbo J, Dzink J, Mitchell G, Cetrulo C, Barlett J. Quantitive Transcervical Uterine Cultures With a New Device. Obstetrics and Gynecology. 1981; 57:243-247; Duff P, Gibbs R, Blanco J, St. Clair P. Endometrial Culture Techniques in Puerperal Patients. Obstetrics and Gynecology. 1983; 61(2):217-222). For the transcervical lavage, a sterile polyionic solution was injected in the endometrium cavity through an inner catheter passing through an outer catheter. This injection was followed by immediate re-aspiration. For the fourth technique, aspiration of lower-uterine secretions, a catheter was placed 4 cm above the external os of the cervix and a polyionic solution was then injected and immediately re-aspirated. These techniques were all conducted on uninfected women in the Trendelenburg position. It was observed that the brush biopsy and lavage through double-lumen catheter were the most satisfactory techniques for reducing but not preventing cervical and vaginal contamination.
The select cell, a newer and smaller version of the Pipelle, is another device used to collect endometrial specimens. (Chambers J T, Chambers S K. Endometrial Sampling: When? Where? Why? With What? Clinical Obstetrics and Gynecology. 1992; 35(1):28-39). The select cell, which removes specimens through suction, is made of a clear, long, and flexible polypropylene sheath with an acetyl copolymer rod to which a piston is molded. As with the transcervical devices, the specimen collected by the select cell is not protected from the contaminated vaginal and cervical areas during sampling.
Several other endometrium samplers and/or techniques have been patented including those described in U.S. Pat. No. 3,777,743 to Binard et al.; U.S. Pat. No. 4,340,066 to Shah; U.S. Pat. No. 4,393,879 to Milgrom; U.S. Pat. No. 4,441,509 to Kotsifas et al.; U.S. Pat. No. 4,949,718 to Neuwirth et al.; U.S. Pat. No. 6,514,224 to Anapliotis; U.S. Pat. No. 8,528,563 to Gruber; U.S. Pat. No. 7,879,559 to Alderete et al.; and U.S. Pat. No. 8,048,101 to Lee-Sepsick et al. However, none of the currently available or patented devices and/or techniques can procure truly uncontaminated specimen samples from the endometrium and surrounding areas. Sterile samples are necessary for a better understanding of not only normal flora in asymptomatic women but also improved understanding and diagnosis of upper genital tract infection in symptomatic women.
The inventors have developed a novel sterile uterine sampler cover (SUSC) device to collect sterile specimen samples from the fallopian tubes, uterus, and surrounding areas to improve the accuracy of diagnosis of pelvic inflammatory disease (PID). Once the disease-causing organism(s) are identified, the proper drug treatment can be recognized. To improve the treatment drug's efficacy, the drug can be encapsulated into nanoparticles for targeted drug delivery. This device can also be used to deliver drug-loaded particles via a transcervical route for more localized drug treatment of PID.
Targeted Drug Delivery
Targeted drug delivery is a unique method for delivering a drug to one particular site of the body in an effort to increase the dosage to that specific location and to reduce adverse side effects. There are three main constituents in a targeted drug delivery system: a drug, a targeted site, and a delivery vehicle. (Patel M P, Patel R R, Patel J K. Chitosan Mediated Drug delivery System: A Review. J Pharm Pharmaceut Sci 2010; 13(3):536-557). The drug can be either chemically conjugated or passively absorbed into the delivery vehicle. The targeted site is dictated by the nature and origin of the disease being treated. The delivery vehicle (the carrier) is of utmost importance, as it must preserve the pharmacodynamic and pharmacokinetic properties of the drug being carried. (Patel M P, Patel R R, Patel J K. Chitosan Mediated Drug delivery System: A Review. J Pharm Pharmaceut Sci 2010; 13(3):536-557).
To deliver a drug across cell membranes, several vehicle materials can be used—e.g., natural or synthetic polymers, dendrimers, surfactants, or lipids. (Sampathkumar S G, Yarem K J. Targeting Cancer Cells Dendrimer. Chemistry & Biology. 2005; 12:5-13; Duncan R. The Dawning Era of Polymer Therapeutic. Nature Reviews Drug Discovery. 2003; 2:347-360; Torchilin V. Antibody-modified liposomes for Cancer Chemotherapy. Expert Opin. Drug Deliv. 2008; 5(9):1003-1025). Among the natural polymers, chitosan is widely used in drug delivery applications because it is biocompatible, biodegradable, and possesses a muco-adhesive property that enables its transport across mucosal membranes. These properties make chitosan highly desirable for encapsulating drugs to improve their efficiency, delivery, and controlled release, and thereby reduce their toxicity. (Zhang H, Oh M, Allen C, Kumacheva E. Monodisperse Chitosan Nanoparticles for Mucosal Drug Delivery. Biomacromolecules. 2004:2461-2468; Xi-Peng G, Da-Ping Q, Kai-Rong L, Tao W, Peng X, Mai K C. Preparation and Characterization of Cationic Chitosan-modified Poly(D,L-lactide-co-glycolide) Copolymer Nanospheres as DNA Carriers. J Biomater Appl. 2007:353-370; Goycoolea F M, Lollo G, Remunan-Lopez G, Quaglia F, Alonso M J. Chitosan-Alginate Blended Nanoparticles as Carriers for the Transmucosal Delivery of Macromolecules. Biomacromolecules. 2009; 10:1736-1743; Zhang H, Wu S, Tao Y, Zang L, Su Z. Preparation and Characterization of Water-Soluble Chitosan Nanoparticles as Protein Delivery System. Journal of Nanomaterials. 2009; 2010:1-5; Racovita S, Vasiliu S, Popa M, Luca C. Polysaccharides based on micro- and nanoparticles obtained by ionic gelation and their application as drug delivery systems. Revue Roumaine de Chimie. 2009; 54(9):709-718; Janes K A, Clavo P, Alonso M J. Polysaccharide colloidal particles as delivery systems for macromolecule. Adv Drug Deliv Rev. 2001; 47:83-97; Patel J K, Jivani N P. Chitosan Based Nanoparticles in Drug Delivery. International Journal of Pharmaceutical Sciences and Nanotechnology. 2009; 2(2):517-522; Muhammed R, Junise V, Saraswathi P, Krishnan P, Dilip C. Development and characterization of chitosan nanoparticles loaded with isoniazid for the treatment of Tuberculosis. Research Journal of Pharmaceutical, Biological and Chemical Sciences. 2010:383-390; Phaechamud T, Charoenteeraboon J. Antibacterial Activity and Drug Release of the Chitosan Sponge Containing Hyclate. AAPS Pharm Sci Tech. 2008; 9(3):829-835; Ko J A, Park H J, Hwang S J, Park J B, Lee J S. Preparation and Characterization of Chitosan Microparticles intended for Controlled Drug Delivery. International Journal of Pharmaceutics. 2002:165-174)
Chitosan is a cationic linear amino-polysaccharide biopolymer derived from the deacetylation of chitin (FIG. 1), which is naturally found in the exoskeleton of crustaceans. (Zhang H, Oh M, Allen C, Kumacheva E. Monodisperse Chitosan Nanoparticles for Mucosal Drug Delivery. Biomacromolecules. 2004:2461-2468; Racovita S, Vasiliu S, Popa M, Luca C. Polysaccharides based on micro- and nanoparticles obtained by ionic gelation and their application as drug delivery systems. Revue Roumaine de Chimie. 2009; 54(9):709-718; Patel J K, Jivani N P. Chitosan Based Nanoparticles in Drug Delivery. International Journal of Pharmaceutical Sciences and Nanotechnology. 2009; 2(2):517-522; Sarmento B, Ribeiro A, Veiga F, Ferreira D. Development and characterization of new insulin containing polysaccharide nanoparticle. Colloids and Surfaces B: Biointerface. 2006; 53:193-202; Tokumitsu H, Ichikawa H, Fukumori Y. Chitosan-Gadopentetic Acid Complex Nanoparticles for Gadolinium Neutron-Capture Therapy Therapy of Cancer: Preparation by Novel Emulsion-Droplet Coalescence Technique and Characterization. Pharmaceutical Research. 1999; 16(12):1830-1835; Pawan P, Mayur M, Ashwin S. Role of Natural Polymers in Sustained Release Drug Delivery System: Application and Recent Approaches. International Research Journal of Pharmacy. 2011; 2(9):6-11; Liu Z, Jiao Y, Wang Y, Zhou C, Zhang Z. Polysaccharides-based nanoparticles as drug delivery systems. Adv Drug Deliv Rev. 2008; 60:1650-1662). When chitosan particles are used to deliver a drug, the patient's body is capable of breaking down the chitosan into non-toxic amino sugars. (Mohanraj V J, Chen Y. Nanoparticle—A Review. Tropical Journal of Pharmaceutical Research. 2006; 5(1):561-573; Nicol S. Life after death for empty shells. New Sci. 1991; 129:46-48). In addition, chitosan particles can be manipulated to achieve both passive and active drug targeting. (Lee-Sepsick K., Azevedo M. S., Currie D. S., Inventors. Methods and Devices for Conduit Occlusion 2009; Agnihotri S A, Mallikarjuna N N, Aminabhavi T M. Recent Advances on chitosan-based micro- and nanoparticles in drug delivery. Journal of Controlled Release. 2004; 100:5-28).
Preparation Methodologies for Chitosan Nanoparticles
Encapsulation methods are chosen in part based on polymer properties, drug hydrophobicity, and desired final particle size. The molecular weight of the chitosan plays a vital role in particle size and formation, as a higher molecular weight produces larger particles. (Tokumitsu H, Ichikawa H, Fukumori Y. Chitosan-Gadopentetic Acid Complex Nanoparticles for Gadolinium Neutron-Capture Therapy Therapy of Cancer: Preparation by Novel Emulsion-Droplet Coalescence Technique and Characterization. Pharmaceutical Research. 1999; 16(12):1830-1835; Moghimi S M, Hunter A C, Murray J C. Long-circulating and target specific nanoparticles: theory to practice. Pharmacol. Rev. 2001; 53(2):283-318). Another vital component of preparing drug-loaded nanoparticles is the hydrophobicity of the drug. (Wang J J, Zeng Z W, Xiao R Z, et al. Recent advances of chitosan nanoparticles as drug carriers. International Journal of Nanomedicine. 2011; 6:765-774). Therefore, the selection of the encapsulation method depends on the desired particle size, drug hydrophobicity, and polymer surface properties to ensure drug encapsulation while minimizing drug loss and maintaining pharmacological activity.
Commonly used methods for preparing chitosan-based drug delivery systems include emulsion cross-linking, emulsion-droplet coalescence, spray drying, sieving, coacervation/precipitation, and ionic gelation. (Muhammed R, Junise V, Saraswathi P, Krishnan P, Dilip C. Development and characterization of chitosan nanoparticles loaded with isoniazid for the treatment of Tuberculosis. Research Journal of Pharmaceutical, Biological and Chemical Sciences. 2010:383-390; Nicol S. Life after death for empty shells. New Sci. 1991; 129:46-48; Wang J J, Zeng Z W, Xiao R Z, et al. Recent advances of chitosan nanoparticles as drug carriers. International Journal of Nanomedicine. 2011; 6:765-774; Tiyaboonchai W. Chitosan Nanoparticles: A Promising System for Drug Deliver. Naresuan University Journal. 2003; 11(3):51-66; Nagpal K, Kumar-Singh S, Nath-Mishr D. Chitosan Nanoparticles: A Promising System in Novel Drug Deliver. Chem. Pharm. Bull. 2010; 58(11):1423-1430; Grenha A, Seijo B, Serra C, Remunan-Lopez C. Chitosan Nanoparticle-Loaded Mannitol Microspheres: Structure and Surface Characterization. Biomacromolecules. 2007; 8:2072-2079; Shanmuganathan S, Shanumugasundaram N, Adhirajan N, Ramyaa-Lakshmi T S, Babu M. Preparation and characterization of chitosan microsphere for doxycycline delivery. Carbohydrate Polymers. 2007:201-211; Pinto-Reis C, Neufeld R J, Ribeiro A J, Veiga F. Nanoencapsulation I. Methods for preparation of drug-loaded polymeric nanoparticles. Nanomedicine. 2006:8-21). Methods such as emulsion cross-linking and emulsion-droplet coalescence involve the use of a harsh crosslinking agent that may induce an unnecessary chemical reaction with the active agents. Spray-drying and sieving produce relatively large microparticles, with diameters of approximately 1-10 μm and 543-698 μm, respectively.
Watzke and Dieschbourg conducted some of the earliest work on preparation of nanoparticles by covalent crosslinking (Clavo P, Vila-Jato J, Alonso M J. Evaluation of catonic polymer coated nanocapsules as ocular drug carriers. Journal of Pharmaceutics. 1997; 153:41-50). They prepared chitosan/silica nano-composites by simply reacting tetramethoxysilane with the hydroxyl on the chitosan polymer. At that point, nanoparticle delivery systems were not yet used to encapsulate pharmaceutically active agents (i.e., drugs). Ohya et al. were the first to present data using chitosan nanospheres for drug delivery applications. (Pawan P, Mayur M, Ashwin S. Role of Natural Polymers in Sustained Release Drug Delivery System: Application and Recent Approaches. International Research Journal of Pharmacy. 2011; 2(9):6-11). They used a water-in-oil emulsion method by crosslinking the amino groups of the chitosan with glutaraldehyde to produce nanospheres loaded with 5-fluorouracil, an anticancer drug. Both of these studies demonstrated the preparation of nano-sized particles that can entrap and deliver drugs. The later discovery of glutaraldehyde's negative impact on cell viability and the integrity of the entrapped drug led to interest in less harsh preparation methods. Ionic gelation is an example of a more benign preparatory method for preparing chitosan nanoparticles.
When chitosan, which is cationic, comes into contact with an anionic compound, it exhibits a unique feature, transitioning from liquid to gel in a process known as ionotropic gelation. The first reported case of using ionic gelation for drug encapsulation using TPP as the crosslinker was that of Bodmeier et al. (Pawan P, Mayur M, Ashwin S. Role of Natural Polymers in Sustained Release Drug Delivery System: Application and Recent Approaches. International Research Journal of Pharmacy. 2011; 2(9):6-11; Watzke H J, Dieschbourg C. Novel silica-biopolymer nanocomposites: the silica sol-gel process in biopolymer organogels. Advances in Colloid and Interface Science. 1994; 50:1-14). This liquid-to-gel process (i.e., gelation) is due to inter- and intramolecular crosslinkages between tripolyphosphate (TPP) phosphates and chitosan amino groups. Their aim was to produce chitosan-TPP beads; however, the results were nanoparticles.
After the Bodmeier findings, other groups used ionic gelation with TPP as the crosslinker for preparing particles. Shirashi et al. encapsulated indomethacin, an acidic drug, into chitosan gel beads. (Ohya Y, Shiratani M, Kobayashi H, Ouchi T. Release Behavior of 5-Fluorouracil from Chitosan-Gel Nanospheres Immobilizing 5-Fluorouracil Coated with Polysaccharides and Their Cell Specific Cytotoxicity. Journal of Macromolecular Science. 1994; 31(5):629-642). Calvo et al. looked at encapsulating protein into chitosan nanoparticles. (Bodmeier R, Chen H, Paeratakul O. A Novel Approach to the Delivery of Microparticles or Nanoparticles Pharm Res. 1989; 6:413-417). Gan et al evaluated the potential of chitosan nanoparticles for delivering gene or protein macromolecules. (Shirashi S, Imani T, Ogtagiri M. Controlled release of indomethacin by chitosan-polyelectrolyte complex optimization and in vivo: in vitro evaluation. J. Control. Release. 1993; 25(3):217-225). Dung et al examined the potential for encapsulating oligonucleotides. (Clavo P, Remunan-Lopez C, Vila-Jata J L, Alonso M J. Chitosan and Chitosan/Ethylene Oxide-Propylene Oxide Block Copolymer Nanoparticles as Novel Carrier for Protein and Vaccines. Pharm Res. 1997; 14(10):1431-1436). Other groups have used ionic gelation to prepare insulin-loaded chitosan nanoparticles. (Gan Q, Wang T, Cochrane C, McCarron P. Modulation of surface charge, particle size and morphological properties of chitosan-TPP nanoparticles intended for gene delivery. Colloids Surf. B Biointerfaces. 2005; 44:65-73; Dung T H, Lee S R, Han S D, et al. Chitosan-TPP nanoparticles as a release system of antiense oligonucleotide in the oral environment. J. Nanosci. Nanotechnol. 2007; 7(11):3695-3699).
The ionic gelation method has been explored to encapsulate many different biomolecules and drugs, but the linkages between the chitosan and TPP are somewhat weak. To asses this weak linkage, Shu et al explored a novel approach to improving the mechanical strength of chitosan beads. (Fernandez-Urrusuno R, Clavo P, Remunan-Lopez C, Vila-Jato J L, Alonso M J. Enhancement of nasal absorption of insulin using chitosan nanoparticles. Pharm. Res. 1999; 16:1576-1581). Xu et al later examined different formulations of chitosan nanoparticles prepared by ionic gelation, assessing the effects of the molecular weight and deacetylation degree of chitosan, the concentration of chitosan, and the initial protein concentration. (Pan Y, Li Y, Zhao H, et al. Chitosan nanoparticles improve the intestinal absorption of insulin in vivo. Int. J. Pharm. 2002; 249:139-147).
Ionic gelation is a novel method for preparing chitosan particles, and it offers clear advantages over other methods. Some of those advantages are its simplicity, fast production process, and freedom from a requirement for complicated equipment. In addition, ionic gelation relies not on chemical crosslinking but on reversible physical crosslinking by electrostatic interaction, which reduces the likelihood of the particles' introducing toxins or causing other undesirable effects. The ionic gelation method also offers the flexibility of producing either microparticles or nanoparticles. (Shu X Z, Zhu K J. A novel approach to prepare tripolyphospate/chitosan complex beads for controlled release drug delivery. Int. J. Pharm. 2000; 201(1):51-58; Xu Y, Du Y. Effect of molecular structure of chitosan on protein delivery properties of chitosan nanoparticles. Int. J. Pharm. 2003; 250(1):215-226).
Despite the significant advantages of the ionic gelation method and the importance of particle size in determining drug-delivery characteristics, definite formulation parameters for producing particles of a specific size range have yet to be defined. In previous work, researchers looked at only one preparatory variable at a time and did not undertake a systematic look at all the preparatory variables simultaneously. The inventors used doxycycline as the model drug for encapsulation, which is a commonly prescribed, inexpensive, broad-spectrum antibiotic. (Boonsongrit Y, Mitrevej A, Mueller B W. Chitosan drug binding by ionic interaction. European Journal of Pharmaceutics and Biopharmaceutics. 2006; 62:267-274).
The inventors have previously demonstrated that encapsulation of doxycycline into chitosan particles can improve drug delivery and the efficacy of the antibiotic while minimizing adverse effects. (Calvo P, Remunan-Lopez C, Vila-Jata J L, Alonso M J. Novel Hydrophilic Chitosanpolyethylene Oxide Nanoparticles as Protein Carriers J. Appl. Polym. Sci. 1997; 63(1):125-132). The inventors examined ionic-gelation preparatory variables and their influence on particle size and morphology. Sixty-four different combinations of chemical constituents and procedural steps were used to generate chitosan nanoparticles of wide-ranging morphology and size. A series of multivariate linear models was constructed to determine the optimum (i.e., most influential) variables for determining particle size.
Doxycycline
Doxycycline is an inexpensive, semi-synthetic antibiotic commonly used as a broad-spectrum drug to treat both intracellular and extracellular bacterial infections. Commonly targeted pathogens include both aerobic and anaerobic gram-positive and gram-negative bacteria and also other microorganisms such as protozoa, mycoplasma, mycobacteria, and spirochetes. (Boonsongrit Y, Mitrevej A, Mueller B W. Chitosan drug binding by ionic interaction. European Journal of Pharmaceutics and Biopharmaceutics. 2006; 62:267-274; Joshi N, Miller D. Doxycycline Revisited. Arch Intern Med. 1997; 157; Cover N, Lai-Yuen S, Parsons A, Kumar A. Synergetic effects of doxycycline-load chitosan nanoparticles for improving drug delivery and efficacy. International Journal of Nanomedicine. 2011; Accepted). Due to doxycycline's antibacterial effects on a wide range of pathogens, it is currently one of the most commonly prescribed antibiotics worldwide for treating infectious diseases such as pelvic inflammatory disease (PID), a polymicrobial infection. (Boonsongrit Y, Mitrevej A, Mueller B W. Chitosan drug binding by ionic interaction. European Journal of Pharmaceutics and Biopharmaceutics. 2006; 62:267-274; Riond J, Riviere J. Pharmacology and Toxicology of Doxycycline. Vet Hum Toxicol. 1988; 30(5):431-443).
For the treatment of diseases such as PID, the CDC recommends 200 mg of doxycycline to be administrated orally or intravenously every 12 hours. (Centers for Disease Control and Prevention. Sexually Transmitted Diseases Treatment Guidelines. MMWR. 2010; 59(No. RR-12):1-109). When administered orally or intravenously, however, doxycycline may cause esophageal ulcers, gastrointestinal irritation, and local inflammation, which may in turn lead to premature cessation of treatment. (Cunha B A, Sibley C M, Ristuccia A M. Doxycycline. Therapeutic Drug Monitoring. 1982:115-135; Cunha B A, Domenico P, Cunha C B. Pharmacodymanics of doxycycline. Clinical Microbiology and Infection. 2001; 6(270-273); Gencosmanoglu R, Kurtkaya-Yapicier O, Tiftikci A, Avsar E, Tozun N, Oran E S. Mid-esophageal ulceration and candidiasis-associated distal esophagitis as two distinct clinical patterns of tetracycline or doxycycline-induced esophageal injury. J Clin Gastroenterol. 2004; 38(6):484-489; Morris T J, Davis T P. Doxycycline-induced esophageal ulceration in the U.S. Military service. Mil Med. 2000; 165(4):316-319). Furthermore, the use of doxycycline may result in mechanical scarring of tissues and cavities in the body, as well as blood vessels. (Tahan V, Sayrak H, Bayar N, Erer B, Tahan G, Dane F. Doxycycline-induced ulceration mimicking esophageal cancer. Cases J. 2008; 1(1):144; Smith K, Leyden J J. Safety of Doxycycline and Minocycline: A Systematic Review. Clinical Therapeutics. 2005; 27(9):1329-1342; Heffner J E, Standerfer R J, Torstveit J, Unruh L. Clinical efficacy of Doxycycline for Pleurodesis. Chest. 1994; 105(6):1743-1747; Mansson T. Treatment of malignant pleural effusion with doxycycline. Scand J Infect Dis Suppl. 1988; 53:29-34; Robinson L A, Fleming W H, Galgraith T A. Intrapleural doxycycline control of malignant pleural effusions. Ann Thorac Surg. 1993; 55:1115-1122).
In recent years, drug encapsulation and delivery via small particles has garnered increasing interest. Encapsulation can help prevent adverse effects by protecting sensitive tissues from fast drug exposure while also improving drug efficacy by achieving slow, sustained release directly at the infection site. Having patients complete the entire treatment cycle would also increase the likelihood of complete pathogen elimination. Encapsulation of doxycycline into biodegradable nanoparticles may be used to improve treatment of PID via direct transcervical drug delivery.
The inventors investigated chitosan nanoparticles as a potential carrier of doxycycline. The inventors assessed particle properties relevant to encapsulated drug delivery through a localized (i.e., transuterine) route. Introducing doxycycline-chitosan nanoparticles to the reproductive lumen produces sustained drug levels in the reproductive tract by adhesion of the particles to the mucosa as well as absorption of the particles into the tissue, thus increasing the likelihood of complete pathogen elimination. The inventors created and then characterized doxycycline-loaded chitosan nanoparticles (DCNPs) in terms of their morphology (size and shape), drug encapsulation efficiency and release rates, in vitro antibacterial activity, and in vitro cytotoxicity.
The inventors have also developed a novel sterile uterine sampler cover (SUSC) device to collect sterile cell samples from the fallopian tubes, uterus and surrounding areas. This device improves the accuracy of diagnosis of pelvic inflammatory disease (PID). The device is designed to collect sterile samples from the uterus that can then be analyzed to identify the specific pathogens causing PID as well as other uterine infections. The device can also be used to deliver nanoencapsulated drugs at the site of infection for targeted drug delivery.